Four Tyres Blown On Landing
On the 6th of October 2022, Turkish Airways flight TK-2256 offered the regularly scheduled service from the Turkish city of Istanbul to Antakya. The flight departed Istanbul slightly late, at 01:43 local time. The aircraft was a Boeing 737-800 registered in Turkey as TC-JVN.
There were six crew and 104 passengers on board for the 95-minute flight.
Hatay Airport at Antakya is located in the lakebed of Lake Amik. The draining of Lake Amik started in 1940, in a project to reclaim land for growing cotton and in hopes of eliminating malaria from the region. The lake was not fully drained until the 1970s. In 2007, Hatay Airport was built in the centre of the lakebed. Turkish Airlines provides regular flights to Antakya from Istanbul and seasonal flights from Frankfurt. The runway configuration is 22/04 asphalt runway of 3,045 metres (9,990 feet).
That evening, flight TK-2256 was uneventful as they approached runway 04. The aircraft touched down at 02:55, right on schedule despite the delayed start.
However, as the Boeing 737 rolled down the runway, all four main-gear tyres burst and caught fire.
The aircraft came to a halt (I’m not sure it had much choice) about 2,000 metres (6560 feet) down the runway, which is within the realms of a normal landing for the 737-800. This would imply that the wheels skidded or locked up happened after the initial touchdown.
The flight crew called ATC immediately and the emergency services quickly responded.
Depending on your email client or browser, you may need to click through to view the videos hosted on Twitter and Instagram.
A video from those moments. pic.twitter.com/RvLmW5ktOW
— Fusa Aviation (@FusaAviation) October 6, 2022
The Aviation Herald entry on this event is sparse but claims that AVHerald has inside information that the aircraft had been dispatched with the Anti-Skid System inoperative.
The Boeing Anti-Skid System is there to provide protection to the main gear wheels in the instance that they are turning too slowly or are locked up completely. The three primary components of the system are wheel speed sensors, control valves and a control box.
There are a few causes of wheel damage or wheels bursting during landing which the Anti-Skid System mitigates. One is the touchdown protection when the brakes are applied in the air before landing. There is also locked wheel protection, in which the sensors show that the wheels are not all turning at the same speed. But the relevant issue here is the anti-skid/hydroplaning protection.
The wheel speed sensor should correspond to the aircraft’s ground speed (taken from the ADIRU). If the wheel speed is too slow, then the system releases the brake on that wheel to allow the wheel speed to increase. This prevents the wheel from skidding, protecting the tyres from the damaged caused by early and excessive braking.
You can see where I’m going with this.
The Minimum Equipment List (MEL) lists the equipment that the aircraft is not required have onboard. I always find the name a little bit confusing. Effectively, instruments and equipment which are not essential to the safety of the flight can be listed on the MEL and the captain can thus take the decision to continue the flight without the listed equipment.
I recommend this video on The Boeing 737 Technical Channel. It offers an overview of the anti-skid system on the 737-800 after an incident last summer, with a much more detailed explanation of the different aspects. It also covers the MEL entry in some detail.
The video confirms that the Anti-Skid System is on that list for the Boeing 737-800, which means that the captain may take the decision to continue the flight without it under certain circumstances.
The flight was evacuated on the runway, using an inflatable slide. Amazingly, there were no injuries during the evacuation.
The fire services laid foam onto the burst tyres and the overheated landing gear.
Turkish Airlines offered the following statement:
“Our Flight TK2256 aircraft operating on the Istanbul (IST) – Hatay (HTY) route suffered a burst tire while landing. As a result, one of the landing gears of the aircraft experienced overheating, to which fire brigade on the scene responded promptly and ensured that it cooled down. Our passengers and crew were safely evacuated without any problems to their physical conditions.” – Yahya Üstün, Senior Vice President Media Relations
The reference to the single tyre is odd as it had been clear immediately that all of the main gear tyres had burst. I’m including the original statement in Turkish in case any Turkish-speaking readers can clarify whether the same mistake is found there:
“TK2256 sefer sayılı İstanbul (IST) – Hatay (HTY) seferinde uçağımızın iniş sırasında lastiği patlamıştır. Bu patlamaya bağlı olarak uçağın iniş takımlarından birinde aşırı ısınma meydana gelmiş ve itfaiye ekipleri iniş sonrası duruma hızlı şekilde müdahale ederek soğutmayı sağlamışlardır. Misafirlerimiz ve ekiplerimiz güvenli şekilde uçaktan tahliye edilmiştir. Sağlık durumlarında bir sorun yoktur. Kamuoyuna saygıyla duyurulur.”
The photographs of the tyres make it clear that the media phrasing of “exploded” is not all that overdramatic.
Boeing 737-800 type aircraft with flight number TK2256 landed hard in Hatay at 02:55 tonight. After the hard landing, the tires on the main landing gear exploded and a fire broke out as a result of overheating. pic.twitter.com/Gws2Y7dIGe
— Fusa Aviation (@FusaAviation) October 6, 2022
Turkish Airlines cancelled all remaining flights that day and the following day as they organised clearing the aircraft off of the runway.
Although there has not been a statement by the Turkish Transport Safety Investigation Center (UEIM), I’m sure they must be setting up for an investigation.
Minor correction: The capital of Turkey is not Istanbul but Ankara.
Dammit. I knew that but lost the plot while trying to get the country reference in. Thanks.
Going by the photographs in the tweet — the tires, where not in contact with the ground, seem to be undamaged, while the lower quarter or so is torn from the rim and melted. The rims seem to be in good shape except where the bottoms have been ground flat against the pavement. I don’t see any scorching or other evidence of fire damage; there probably wasn’t any fire to put out, just overheated wheels to be cooled down.
On the whole, the damage to the tires and rims seems to indicate that the wheels never rotated at all after the aircraft touched down.
That’s interesting! So that would point to brakes applied before touchdown, but then I’m surprised at the distance they appeared to have travelled before stopping.
If skidding tires braked better, we wouldn’t need anti-skid—but they don’t, so the stopping distance shouldn’t be shorter.
Thankfully the aircraft didn’t lose the nose wheel (is it exempt from braking?) and thus had steering, otherwise a runway excursion would’ve been likely.
Mendel, I am not so sure of that.
But whether or not the stopping distance is better with anti-skid functioning, the aircraft at least can taxy to the terminal if the tyres and rims are not damaged.
It has happened to me once. I was training captain on the Citation and checking another pilot out.
Part of the exercise was an abandoned take-off close to V1.
Which involved maximum braking after the call “STOP-STOP” as per SOP in the company.
The wheels locked and the main tyres blew out; there also was considerable damage to the rims.
Investigation showed that there was a wiring fault in the system: the anti-skid system was not working, but the warning on the CAP did not illuminate. We were exonerated, the other pilot passed the check.
It was just as well, because we did operate from airports with critically short runways and were never aware that the anti-skid was not operational until this incident, which took place on a very long runway.
The aircraft came to a stop very quickly, but we never checked if it was shorter than with anti-skid (and of course undamaged wheels).
Mendel: IIUC, the reason for “antilock” (i.e., anti-skid) brakes on cars is that a skidding tire can’t be steered; if it isn’t gripping the road the car may continue in the same direction regardless of what the driver does with the steering wheel, or it may move unpredictably. A skidding stop might be shorter, but it might not be in the same lane — or it might be in multiple lanes. I suspect the same thing applies to airplanes.
I notice that at least two people were foolish enough to be taking pictures instead of getting as far from the flames as possible. (There’s someone using a phone in the shots Sylvia put in this post, and the camera work in the shots doesn’t look deliberate.) I’m not surprised nobody got hurt coming down the slide as it’s a developed technology, and not so severe a crash as (e.g.) Air France 358 (landed long at Toronto, ran off the end of the runway, burned spectacularly with 4 failed exits leading to some people jumping out), but some day some idiot with a camera phone is going to get hurt after getting safely onto solid ground.
Yes and no. Anti-lock on cars is very much for that reason – locked-up wheels cannot contribute to steering.
And now the caveats:
Rolling wheels also have greater friction than skidding wheels – it’s the difference between static friction (rolling wheels are effectively in static contact with the ground) and dynamic friction, which is significantly less. Generally speaking, a rolling wheel has greater traction than a sliding wheel (This is why objects on inclined planes continue to slide, once poked into moving).
Anti-lock systems in cars are conservatively designed. They release braking before the maximum effort is applied, because they do not want to lock up under any circumstances (see 1st above). Very good drivers who know their cars intimately can brake harder than anti-lock systems will let them, because they can hold the braking right at the threshold of skidding, while the anti-lock systems will let go earlier, for the safety margin. Formula One champion drivers do this – and they still lock up now and then (at tremendous cost to their lap times).
Also worth noting is that this applies to tires. When you’re grinding the rims into the asphalt, the braking no longer is limited to rubber on the surface, but metal actively plowing up the surface, causing vastly greater stopping force (as Sylvia pointed out – “[N]ot sure it had much choice”) in the same way that stopping on your tires is not quite the same as stopping by hitting a brick wall.
So, yeah. Yes and no. Like many things, “It’s complicated.” ;-)
Correct Jon ! In theory wheels that do not lock (ABS) will enable the vehicle to stop more quickly than if they were. And yes, it is difficult to steer a vehicle with locked wheels. But you are right, the ABS will react a split second early. So even if it will not be the quickest way to stop, there is the associated tyre damage of a locked wheel. And a locked wheel will aquaplane if there is a film of water on the surface of the runway.
The anti-lock systems on modern aircraft are very sophisticated and very efficient. They incorporate refinements such as skid control as previous contributors mentioned. They will normally bring the aircraft to a stop much more quickly. But having said that, the car industry is catching up.
Of course, braking action will have to be taken into account. Pilots will normally get a “Snowtam” in their pre-flight briefing and the ATIS will inform them of the actual status.
If the runway is very slippery, (braking action poor) there is no way knowing what will happen, anti-skid or not.
Worse:in extreme circumstances use of reverse thrust can be very tricky, especially in a crosswind.
The wind will simultaneously try to blow the aircraft to the (downwind) side of the runway and turn it into a weathercock. The only remedy may be to add asymmetric forward power again, not something one wants to do if the runway is covered in snow or worse: black ice and the runway end is coming up.. In those circumstances there is only one remedy: don’t even try! Divert!